Input pump pulse energy optimisation to maximise four-wave mixing conversion efficiency in semiconductor optical amplifier

We analyse the influence of input pump pulse energy on the four-wave mixing (FWM) conversion efficiency in semiconductor optical amplifiers (SOAs). For the simulation of the wave propagation in the SOA, we use the nonlinear propagation equation taking into account the gain spectrum dynamics, gain saturation which depends on carrier depletion, carrier heating, spectral hole-burning, group velocity dispersion, self-phase modulation and two photon absorption. The simulation results confirm that corresponding to each input probe pulse energy, there is an optimum input pump energy that maximises the FWM conversion efficiency in the SOA. The configuration of the SOA input pump pulse energy is organised to maximise the FWM conversion efficiency, which is very much useful in practical communication systems. It is shown that energy of the generated FWM pulse will remain constant when the input pump energy increases further from the optimum input pump energy. Moreover, FWM conversion efficiency will decrease when the input pump energy increases further from the optimum input pump energy.